https://www.rosieonthehouse.com/faqs/how-do-i-turn-off-the-electricity-to-my-whole-house

How do I turn off the electricity to my whole house?

If you  have a gas leak, it’s a good idea to shut off your home’s electricity as well as the gas. Likewise, if a plumbing leak floods your house, you’ll want the power off. 

You can turn the electricity off inside your circuit breaker panel or fuse box. You would usually do this only in an extreme emergency. 

Before you face that emergency, locate your box. It might be in a utility closet or the basement, if you have one. It’s a metal box full of switches or fuses.
 
If your box is full of switches, they control your home’s electrical circuits. Turn all of them to the “off” position, and then switch off the main switch at the top.
 
Two cautions:

  • If your floor is flooded or if the electrical panel is wet, do not touch the panel. 
  • If you see exposed wires inside the box, do not touch them. In both cases, call the electric company or an electrician to handle this dangerous task.
Don’t flip the main switch except for during an emergency. If you’re having a problem with electricity in a particular room or with one appliance, you can flip the switch that powers just that area. Often, you’ll find that the individual switch is “off,” and you can solve the problem by turning it back on.

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